Change Body Class Based On URL in Meteor

I have a template named layout in my app. Inside has:

<body id="body class="{{blue}}>

Basically what I want to achieve is that when you hit a url, for example, www.abc.com/sky, I want to add a body class of blue:

<body id="body class="blue">

In my client folder I have this but seems not to work:

Template.layout.helpers({
  blue: function() {
    var loc = window.location.href; // returns the full URL
    if(/sky/.test(loc)) {
    $('#body').addClass('blue');
    }
  }
});

I am new to the javascript world and I am following a tutorial but the tutorial was not aimed for Meteor.

Solution

You shold modify DOM elememts in onRendered like this:

Template.layout.onRendered(function() {
  // get the current route name (better than checking window.location)
  var routeName = Router.current().route.getName();

  // add the class to body if this is the correct route
  if (routeName === 'myRoute')
    $('body').addClass('blue');
});

Template.layout.onDestroyed(function() {
  // remove the class to it does not appear on other routes
  $('body').removeClass('blue');
});

An alternative (and probably easier) solution is just to use a helper on your body template:

Template.body.helpers({
  klass: function() {
    if (Router.current().route.getName() === 'myRoute') {
      return 'blue';
    }
  }
});

Then your body could look like this:

<body class="{{klass}}"></body>